Fiber reinforced resin formed by impregnating carbon or glass fiber with resin is known. The fiber reinforced resin has special characteristics of being lightweight and having high strength.
In a molded article molded from the fiber reinforced resin by, for example, press working, a cross-section is often bared at an edge or end. In this case, the fiber may be exposed on the cross-section of the molded article and the exposed fiber may fall out of the cross-section. For example, carbon fiber that falls out of the inner peripheral surface of a through-hole formed in the molded article and contacts the skin may cause itching.
For this reason, the cross-section of the molded article of the fiber reinforced resin needs to be processed to prevent the fiber from being exposed on the cross-section. For example, the molded article must be subjected to, for example, insert molding to perform processing such as covering the cross-section with resin. Therefore, the cross-section of the molded article is required to be processed more efficiently when molding the fiber reinforced resin.